Twenty years after the introduction of the theory, we revisit what it does—and doesn’t—explain. by Clayton M. Christensen, Michael E. Raynor and Rory McDonald Please enjoy this HBR Classic. Clayton M.

Creatine monohydrate is the most widely used, recommended, and studied form of creatine. Other types include creatine ethyl ester, hydrochloride, and magnesium creatine, but less research supports ...